Microstrip antennas for wireless power transmitters

ABSTRACT

A microstrip antenna for use in a wireless power transmission system and a method for forming the microstrip antenna are described. The antenna includes a first multi-layer printed circuit board (PCB) that includes a top surface and a bottom surface. The top and bottom surfaces of the first multi-layer PCB include a first electrically conductive material. The antenna includes a second multi-layer PCB that includes a top surface and a bottom surface. The top and bottom surfaces of the second multi-layer PCT include a second electrically conductive material. A first plurality of vias each substantially pass through the top and bottom surfaces of the first multi-layer PCB. A second plurality of vias each substantially pass through the top and bottom surfaces of the second multi-layer PCB. The antenna further comprises a dielectric slab that is configured to receive the first multi-layer PCB and the second multi-layer PCB.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No. 15/414,464, filed on Jan. 24, 2017, entitled “Microstrip Antennas For Wireless Power Transmitters,” which is hereby incorporated by reference in its entirety.

TECHNICAL FIELD

The disclosed embodiments relate generally to wireless power transmission systems, and in particular, to microstrip antennas for wirelessly transmitting and/or receiving power.

BACKGROUND

Portable electronic devices, such as laptop computers, mobile phones, tablets, and other electronic devices, require frequent charging of a power-storing component (e.g., a battery) to operate. Many electronic devices require charging one or more times per day. Often, charging an electronic device requires manually connecting an electronic device to an outlet or other power source using a wired charging cable. In some cases, the power-storing component is removed from an electronic device and inserted into charging equipment. Accordingly, charging is time consuming, burdensome, and inefficient because users must carry around multiple charging cables and/or other charging devices, and frequently must locate appropriate power sources to charge their electronic devices. Additionally, conventional charging techniques potentially deprive a user of the ability to use the device while it is charging, and/or require the user to remain next to a wall outlet or other power source to which their electronic device or other charging equipment is connected.

Additionally, existing patch antennas used for transmission of power waves have large cross-sectional areas, such as 6″ by 6″ for transmission of power waves at a frequency of 900 MHz. Due to these large cross-sectional areas, integrating these existing patch antennas with consumer electronic devices results in noticeable and undesired changes to an aesthetic appearance of the consumer electronic devices, thereby reducing the likelihood that consumers will be willing to install such devices in their homes, office spaces, and other areas.

SUMMARY

There is a need for improved antenna designs that help to address the shortcomings of conventional charging systems described above. In particular, there is a need for antennas (e.g., microstrip antennas) that have a form factor that is suitable for integration with consumer devices. The antennas described herein address these shortcomings and have a form factor that is suitable for integration with consumer devices. For example, in some embodiments the antennas discussed herein have a largest cross-sectional dimension of approximately two inches, making integration with consumer devices such as sound bars, televisions, media entertainment systems, light fixtures, portable air conditioning/heater systems, dashboard and glove compartments in automobiles, devices embedded in seat-backs (e.g., in trains, busses and airplanes), advertisement panels, and other consumer devices appropriate without impacting aesthetic appeal of these consumer devices, thereby ensuring that consumers will be more receptive to installing such transmitter devices (e.g., a sound bar with the novel microstrip antenna integrated therein) in their homes, offices, and other spaces.

In some embodiments, an antenna for use in a wireless power transmission system includes a first multi-layer printed circuit board (PCB) that includes a top surface and a bottom surface that is opposite the top surface, and the top and bottom surfaces of the first multi-layer PCB include a first electrically conductive material. The antenna additionally comprises a second multi-layer PCB that includes a top surface and a bottom surface that is opposite the top surface, and the top and bottom surfaces of the second multi-layer PCT include a second electrically conductive material. A first plurality of vias each substantially pass through the top and bottom surfaces of the first multi-layer PCB. A second plurality of vias each substantially pass through the top and bottom surfaces of the second multi-layer PCB. The antenna further includes a dielectric slab that is configured to receive the first multi-layer PCB and the second multi-layer PCB.

In some embodiments, a method for forming an antenna includes forming a dielectric assembly by coupling a dielectric slab to a first multi-layer PCB and a second multi-layer PCB. The first multi-layer PCB includes a top surface and a bottom surface that is opposite the top surface. The top and bottom surfaces of the first multi-layer PCB include a first electrically conductive material. A first plurality of vias each substantially pass through the top and bottom surfaces of the first multi-layer PCB. The second multi-layer PCB includes a top surface and a bottom surface that is opposite the top surface. The top and bottom surfaces of the second multi-layer PCT include a second electrically conductive material. A second plurality of vias each substantially pass through the top and bottom surfaces of the second multi-layer PCB. The method also includes coupling at least one feed to the dielectric assembly.

Note that the various embodiments described above can be combined with any other embodiments described herein. The features and advantages described in the specification are not all inclusive and, in particular, many additional features and advantages will be apparent to one of ordinary skill in the art in view of the drawings, specification, and claims. Moreover, it should be noted that the language used in the specification has been principally selected for readability and instructional purposes, and may not have been selected to delineate or circumscribe the inventive subject matter.

BRIEF DESCRIPTION OF THE DRAWINGS

So that the present disclosure can be understood in greater detail, a more particular description may be had by reference to the features of various embodiments, some of which are illustrated in the appended drawings. The appended drawings, however, merely illustrate pertinent features of the present disclosure and are therefore not to be considered limiting, for the description may admit to other effective features.

FIG. 1 illustrates components of a wireless power transmission system, in accordance with some embodiments.

FIG. 2 illustrates a cross-sectional view of a microstrip antenna, in accordance with some embodiments.

FIG. 3 illustrates a top view of a multi-layer PCB, in accordance with some embodiments.

FIG. 4 is used to illustrate dimensions of a microstrip antenna, in accordance with some embodiments.

FIG. 5 is an expanded view of a multi-layer PCB that illustrates a material formed on the interior surfaces of vias, in accordance with some embodiments.

FIG. 6 illustrates an array of microstrip antennas, in accordance with some embodiments.

FIGS. 7A-7C are a flowchart representation of a method for forming an antenna, in accordance with some embodiments.

In accordance with common practice, the various features illustrated in the drawings may not be drawn to scale. Accordingly, the dimensions of the various features may be arbitrarily expanded or reduced for clarity. In addition, some of the drawings may not depict all of the components of a given system, method or device. Finally, like reference numerals may be used to denote like features throughout the specification and figures.

DETAILED DESCRIPTION

Numerous details are described herein in order to provide a thorough understanding of the example embodiments illustrated in the accompanying drawings. However, some embodiments may be practiced without many of the specific details, and the scope of the claims is only limited by those features and aspects specifically recited in the claims. Furthermore, well-known processes, components, and materials have not been described in exhaustive detail so as not to unnecessarily obscure pertinent aspects of the embodiments described herein.

A microstrip antenna is described herein, which address the shortcomings described above in conventional charging systems and with existing antenna designs. In some embodiments, the microstrip antenna described herein is a component of a transmitter and/or a receiver of a wireless power transmission environment 100 (e.g., as described with regard to FIG. 1). For example, a microstrip antenna transmits power waves and/or receives transmitted power waves.

In some embodiments, one or more transmitters of a wireless power transmission environment generate power waves to form pockets of energy at target locations and adjust power wave generation based on sensed data to provide safe, reliable, and efficient wirelessly-delivered power to receivers (and devices associated therewith). In some embodiments, a controlled “pocket of energy” (e.g., a region in which available power is high due to constructive interference of power waves) and/or null spaces (e.g., a region in which available power is low or nonexistent due to destructive interference of power waves) may be formed by convergence of the power waves transmitted into a transmission field of the one or more transmitters. In some embodiments, the one or more transmitters include an array of the microstrip antennas described herein (e.g., in reference to FIGS. 2-7C), and the array of the microstrip antennas is used to transmit the power waves. For example, the antennas discussed herein may be integrated with consumer devices such as sound bars, televisions, media entertainment systems, light fixtures, and other consumer devices, to produce a respective transmitter that remains aesthetically appealing, yet still capable of transmitting power waves sufficient to charge other electronic devices (e.g., cell phones, smart watches, etc.).

In some embodiments, pockets of energy form at one or more locations in a two- or three-dimensional field due to patterns of constructive interference caused by convergences of transmitted power waves. Energy from the transmitted power waves may be harvested by receivers (i.e., received and converted into usable power) at the one or more locations.

In some embodiments, adaptive pocket-forming is performed, e.g., by adjusting power wave transmission to achieve a target power level for at least some of the power waves transmitted by the one or more transmitters. For example, a system for adaptive pocket-forming includes a sensor. In some embodiments, when the sensor detects an object, such as a sensitive object (e.g., a person, an animal, equipment sensitive to the power waves, and the like) within a predetermined distance (e.g., a distance within a range of 1-5 feet) of a pocket of energy, of one or more of the power waves, or of a transmitter, then a respective transmitter of the one or more transmitters adjusts one or more characteristics of transmitted power waves. Non-limiting examples of the one or more characteristics include: frequency, amplitude, trajectory, phase, and other characteristics used by one or more antennas of the one or more transmitters to transmit the power waves. As one example, in response to receiving information indicating that transmission of power waves by a respective transmitter of the one or more transmitters should be adjusted (e.g., a sensor senses a sensitive object within a predetermined distance of a respective target location), the adaptive pocket-forming process adjusts the one or more characteristics accordingly.

In some embodiments, adjusting the one or more characteristics includes reducing a currently generated power level at a location by adjusting one or more transmitted power waves that converge at the target location. In some embodiments, reducing a currently generated power level includes transmitting a power wave that causes destructive interference with at least one other transmitted power wave. For example, a power wave is transmitted with a first phase that is shifted relative to a second phase of at least one other power wave to destructively interfere with the at least one other power wave in order to diminish or eliminate the currently generated power level at the target location.

In some embodiments, adjusting the one or more characteristics includes increasing a power level for some of the transmitted power waves to ensure that the receiver receives adequate energy sufficient to quickly charge a power-storing component of an electronic device that is associated with the receiver.

In some embodiments, an object is “tagged” (e.g., an identifier of the object is stored in memory in association with a flag) to indicate that the detected object is a sensitive object. In response to detection of a particular object within a predetermined distance of a target location, a determination is made as to whether the particular object is a sensitive object. In some embodiments, this determination includes performing a lookup in the memory to check whether the particular object has been previously tagged and is therefore known as a sensitive object. In response to determining that the particular object is a sensitive object, the one or more characteristics used to transmit the power waves are adjusted accordingly.

In some embodiments, sensing a sensitive object includes using a series of sensor readings from one or more sensors to determine motion of an object within a transmission field of the one or more transmitters. In some embodiments, sensor output from one or more sensors is used to detect motion of the object approaching within a predetermined distance of a pocket of energy or of power waves used to form the pocket of energy. In response to a determination that a sensitive object is approaching (e.g., moving toward and/or within a predefined distance of a pocket of energy), the currently generated power level at the location of the pocket of energy is reduced. In some embodiments, the one or more sensors include sensors that are internal to the one or more transmitters and/or the receiver. In some embodiments, the one or more sensors include sensors that are external to the one or more transmitters and the receiver. In some embodiments, the one or more sensors include thermal imaging, optical, radar, and other types of sensors capable of detecting objects within a transmission field.

Although some embodiments herein include the use of RF-based wave transmission technologies as a primary example, it should be appreciated that the wireless charging techniques that might be employed are not be limited to RF-based technologies and transmission techniques. Rather, it should be appreciated that additional or alternative wireless charging techniques may be utilized, including any suitable technology and technique for wirelessly transmitting energy so that a receiver is capable of converting the transmitted energy to electrical power. Such technologies or techniques may transmit various forms of wirelessly transmitted energy including the following non-limiting examples: ultrasound, microwave, laser light, infrared, or other forms of electromagnetic energy.

FIG. 1 is a block diagram of components of wireless power transmission environment 100, in accordance with some embodiments. Wireless power transmission environment 100 includes, for example, transmitters 102 (e.g., transmitters 102 a, 102 b . . . 102 n) and one or more receivers 120 (e.g., receivers 120 a, 120 b . . . 120 n). In some embodiments, each respective wireless power transmission environment 100 includes a number of receivers 120, each of which is associated with a respective electronic device 122.

An example transmitter 102 (e.g., transmitter 102 a) includes, for example, one or more processor(s) 104, a memory 106, one or more antenna arrays 110 (e.g., including antenna elements structured as described below in reference to FIGS. 2-7C), and one or more communications components 112, and/or one or more transmitter sensors 114. In some embodiments, these components are interconnected by way of a communications bus 108. References to these components of transmitters 102 cover embodiments in which one or more than one of each of these components (and combinations thereof) are included.

In some embodiments, memory 106 stores one or more programs (e.g., sets of instructions) and/or data structures, collectively referred to as “modules” herein. In some embodiments, memory 106, or the non-transitory computer readable storage medium of memory 106 stores the following modules 107 (e.g., programs and/or data structures), or a subset or superset thereof:

-   -   information received from receiver 120 (e.g., generated by         receiver sensor 128 and then transmitted to the transmitter 102         a);     -   information received from transmitter sensor 114;     -   an adaptive pocket-forming module that adjusts one or more power         waves transmitted by one or more transmitters 102; and/or     -   a beacon transmitting module that transmits a communication         signal 118 for detecting a receiver 120 (e.g., within a         transmission field of the one or more transmitters 102).

The above-identified modules (e.g., data structures and/or programs including sets of instructions) need not be implemented as separate software programs, procedures, or modules, and thus various subsets of these modules may be combined or otherwise re-arranged in various embodiments. In some embodiments, memory 106 stores a subset of the modules identified above. In some embodiments, an external mapping memory 131 that is communicatively connected to communications component 112 stores one or more modules identified above. Furthermore, the memory 106 and/or external mapping memory 131 may store additional modules not described above. In some embodiments, the modules stored in memory 106, or a non-transitory computer readable storage medium of memory 106, provide instructions for implementing respective operations in the methods described below. In some embodiments, some or all of these modules may be implemented with specialized hardware circuits that subsume part or all of the module functionality. One or more of the above-identified elements may be executed by one or more of processor(s) 104. In some embodiments, one or more of the modules described with regard to memory 106 is implemented on memory 104 of a server (not shown) that is communicatively coupled to one or more transmitters 102 and/or by a memory of electronic device 122 and/or receiver 120.

In some embodiments, a single processor 104 (e.g., processor 104 of transmitter 102 a) executes software modules for controlling multiple transmitters 102 (e.g., transmitters 102 b . . . 102 n). In some embodiments, a single transmitter 102 (e.g., transmitter 102 a) includes multiple processors 104, such as one or more transmitter processors (configured to, e.g., control transmission of signals 116 by antenna array 110), one or more communications component processors (configured to, e.g., control communications transmitted by communications component 112 and/or receive communications by way of communications component 112) and/or one or more sensor processors (configured to, e.g., control operation of transmitter sensor 114 and/or receive output from transmitter sensor 114).

Receiver 120 (e.g., a receiver of electronic device 122) receives power signals 116 and/or communications 118 transmitted by transmitters 102. In some embodiments, receiver 120 includes one or more antennas 124 (e.g., antenna array including multiple antenna elements), power converter 126, receiver sensor 128 and/or other components or circuitry (e.g., processor(s) 140, memory 142, and/or communication component(s) 144). In some embodiments, these components are interconnected by way of a communications bus 143. References to these components of receiver 120 cover embodiments in which one or more than one of each of these components (and combinations thereof) are included. Receiver 120 converts energy from received signals 116 (e.g., power waves) into electrical energy to power and/or charge electronic device 122. For example, receiver 120 uses power converter 126 to convert captured energy from power waves 116 to alternating current (AC) electricity or direct current (DC) electricity usable to power and/or charge electronic device 122. Non-limiting examples of power converter 126 include rectifiers, rectifying circuits, voltage conditioners, among suitable circuitry and devices.

In some embodiments, receiver 120 is a standalone device that is detachably coupled to one or more electronic devices 122. For example, electronic device 122 has processor(s) 132 for controlling one or more functions of electronic device 122 and receiver 120 has processor(s) 140 for controlling one or more functions of receiver 120.

In some embodiments, receiver is a component of electronic device 122. For example, processor(s) 132 controls functions of electronic device 122 and receiver 120.

In some embodiments, electronic device 122 includes processor(s) 132, memory 134, communication component(s) 136, and/or battery/batteries 130. In some embodiments, these components are interconnected by way of a communications bus 138. In some embodiments, communications between electronic device 122 and receiver 120 occur via communications component(s) 136 and/or 144. In some embodiments, communications between electronic device 122 and receiver 120 occur via a wired connection between communications bus 138 and communications bus 146. In some embodiments, electronic device 122 and receiver 120 share a single communications bus.

In some embodiments, receiver 120 receives one or more power waves 116 directly from transmitter 102. In some embodiments, receiver 120 harvests power waves from one or more pockets of energy created by one or more power waves 116 transmitted by transmitter 102.

In some embodiments, after the power waves 116 are received and/or energy is harvested from a pocket of energy, circuitry (e.g., integrated circuits, amplifiers, rectifiers, and/or voltage conditioner) of the receiver 120 converts the energy of the power waves (e.g., radio frequency electromagnetic radiation) to usable power (i.e., electricity), which powers electronic device 122 and/or is stored to battery 130 of electronic device 122. In some embodiments, a rectifying circuit of the receiver 120 translates the electrical energy from AC to DC for use by electronic device 122. In some embodiments, a voltage conditioning circuit increases or decreases the voltage of the electrical energy as required by the electronic device 122. In some embodiments, an electrical relay conveys electrical energy from the receiver 120 to the electronic device 122.

In some embodiments, receiver 120 is a component of an electronic device 122. In some embodiments, a receiver 120 is coupled (e.g., detachably coupled) to an electronic device 122. In some embodiments, electronic device 122 is a peripheral device of receiver 120. In some embodiments, electronic device 122 obtains power from multiple transmitters 102 and/or using multiple receivers 120. In some embodiments, the wireless power transmission environment 100 includes a plurality of electronic devices 122, each having at least one respective receiver 120 that is used to harvest power waves from the transmitters 102 into usable power for charging the electronic devices 122.

In some embodiments, the one or more transmitters 102 adjust one or more characteristics (e.g., phase, gain, direction, and/or frequency) of power waves 116. For example, a transmitter 102 (e.g., transmitter 102 a) selects a subset of one or more antenna elements of antenna array 110 to initiate transmission of power waves 116, cease transmission of power waves 116, and/or adjust one or more characteristics used to transmit power waves 116. In some implementations, the one or more transmitters 102 adjust power waves 116 such that trajectories of power waves 116 converge at a predetermined location within a transmission field (e.g., a location or region in space), resulting in controlled constructive or destructive interference patterns.

In some embodiments, respective antenna arrays 110 of the one or more transmitters 102 may include a set of one or more antennas configured to transmit the power waves 116 into respective transmission fields of the one or more transmitters 102. Integrated circuits (not shown) of the respective transmitter 102, such as a controller circuit and/or waveform generator, may control the behavior of the antennas. For example, based on the information received from the receiver by way of the communications signal 118, a controller circuit may determine a set of one or more characteristics or waveform characteristics (e.g., amplitude, frequency, trajectory, phase, among other characteristics) used for transmitting the power waves 116 that would effectively provide power to the receiver 102 and electronic device 122. The controller circuit may also identify a subset of antennas from the antenna arrays 110 that would be effective in transmitting the power waves 116. As another example, a waveform generator circuit of the respective transmitter 102 coupled to the processor 104 may convert energy and generate the power waves 116 having the waveform characteristics identified by the controller, and then provide the power waves to the antenna arrays 110 for transmission.

In some embodiments, constructive interference of power waves occurs when two or more power waves 116 are in phase with each other and converge into a combined wave such that an amplitude of the combined wave is greater than amplitude of a single one of the power waves. For example, the positive and negative peaks of sinusoidal waveforms arriving at a location from multiple antennas “add together” to create larger positive and negative peaks. In some embodiments, a pocket of energy is formed at a location in a transmission field where constructive interference of power waves occurs.

In some embodiments, destructive interference of power waves occurs when two or more power waves are out of phase and converge into a combined wave such that the amplitude of the combined wave is less than the amplitude of a single one of the power waves. For example, the power waves “cancel each other out,” thereby diminishing the amount of energy concentrated at a location in the transmission field. In some embodiments, destructive interference is used to generate a negligible amount of energy or “null” at a location within the transmission field where the power waves converge.

In some embodiments, the one or more transmitters 102 transmit power waves 116 that create two or more discrete transmission fields (e.g., overlapping and/or non-overlapping discrete transmission fields). In some embodiments, a first transmission field is managed by a first processor 104 of a first transmitter (e.g. transmitter 102 a) and a second transmission field is managed by a second processor 104 of a second transmitter (e.g., transmitter 102 b). In some embodiments, the two or more discrete transmission fields (e.g., overlapping and/or non-overlapping) are managed by the transmitter processors 104 as a single transmission field.

In some embodiments, communications component 112 transmits communication signals 118 by way of a wired and/or wireless communication connection to receiver 120. In some embodiments, communications component 112 generates communications signals 118 used for triangulation of receiver 120. In some embodiments, communication signals 118 are used to convey information between transmitter 102 and receiver 120 for adjusting one or more characteristics used to transmit the power waves 116. In some embodiments, communications signals 118 include information related to status, efficiency, user data, power consumption, billing, geo-location, and other types of information.

In some embodiments, receiver 120 includes a transmitter (not shown), or is a part of a transceiver, that transmits communications signals 118 to communications component 112 of transmitter 102.

In some embodiments, communications component 112 (e.g., communications component 112 of transmitter 102 a) includes a communications component antenna for communicating with receiver 120 and/or other transmitters 102 (e.g., transmitters 102 b through 102 n). In some embodiments, these communications signals 118 represent a distinct channel of signals transmitted by transmitter 102, independent from a channel of signals used for transmission of the power waves 116.

In some embodiments, the receiver 120 includes a receiver-side communications component (not shown) configured to communicate various types of data with one or more of the transmitters 102, through a respective communications signal 118 generated by the receiver-side communications component. The data may include location indicators for the receiver 102 and/or electronic device 122, a power status of the device 122, status information for the receiver 102, status information for the electronic device 122, status information about the power waves 116, and/or status information for pockets of energy. In other words, the receiver 102 may provide data to the transmitter 102, by way of the communications signal 118, regarding the current operation of the system 100, including: information identifying a present location of the receiver 102 or the device 122, an amount of energy received by the receiver 120, and an amount of power received and/or used by the electronic device 122, among other possible data points containing other types of information.

In some embodiments, the data contained within communications signals 118 is used by electronic device 122, receiver 120, and/or transmitters 102 for determining adjustments of the one or more characteristics used by the antenna array 110 to transmit the power waves 106. Using a communications signal 118, the transmitter 102 communicates data that is used, e.g., to identify receivers 120 within a transmission field, identify electronic devices 122, determine safe and effective waveform characteristics for power waves, and/or hone the placement of pockets of energy. In some embodiments, receiver 120 uses a communications signal 118 to communicate data for, e.g., alerting transmitters 102 that the receiver 120 has entered or is about to enter a transmission field, provide information about electronic device 122, provide user information that corresponds to electronic device 122, indicate the effectiveness of received power waves 116, and/or provide updated characteristics or transmission parameters that the one or more transmitters 102 use to adjust transmission of the power waves 116.

As an example, the communications component 112 of the transmitter 102 communicates (e.g., transmits and/or receives) one or more types of data (including, e.g., authentication data and/or transmission parameters) including various information such as a beacon message, a transmitter identifier, a device identifier for an electronic device 122, a user identifier, a charge level for electronic device 122, a location of receiver 120 in a transmission field, and/or a location of electronic device 122 in a transmission field.

In some embodiments, transmitter sensor 114 and/or receiver sensor 128 detect and/or identify conditions of electronic device 122, receiver 120, transmitter 102, and/or a transmission field. In some embodiments, data generated by transmitter sensor 114 and/or receiver sensor 128 is used by transmitter 102 to determine appropriate adjustments to the one or more characteristics used to transmit the power waves 106. Data from transmitter sensor 114 and/or receiver sensor 128 received by transmitter 102 includes, e.g., raw sensor data and/or sensor data processed by a processor 104, such as a sensor processor. Processed sensor data includes, e.g., determinations based upon sensor data output. In some embodiments, sensor data received from sensors that are external to the receiver 120 and the transmitters 102 is also used (such as thermal imaging data, information from optical sensors, and others).

In some embodiments, receiver sensor 128 is a gyroscope that provides raw data such as orientation data (e.g., tri-axial orientation data), and processing this raw data may include determining a location of receiver 120 and/or or a location of receiver antenna 124 using the orientation data.

In some embodiments, receiver sensor 128 includes one or more infrared sensors (e.g., that output thermal imaging information), and processing this infrared sensor data includes identifying a person (e.g., indicating presence of the person and/or indicating an identification of the person) or other sensitive object based upon the thermal imaging information.

In some embodiments, receiver sensor 128 includes a gyroscope and/or an accelerometer that indicates an orientation of receiver 120 and/or electronic device 122. As one example, transmitters 102 receive orientation information from receiver sensor 128 and the transmitters 102 (or a component thereof, such as the processor 104) use the received orientation information to determine whether electronic device 122 is flat on a table, in motion, and/or in use (e.g., next to a user's head).

In some embodiments, receiver sensor 128 is a sensor of electronic device 122 (e.g., an electronic device 122 that is remote from receiver 102). In some embodiments, receiver 120 and/or electronic device 122 includes a communication system for transmitting signals (e.g., sensor signals output by receiver sensor 128) to transmitter 102.

Non-limiting examples of transmitter sensor 114 and/or receiver sensor 128 include, e.g., infrared, pyroelectric, ultrasonic, laser, optical, Doppler, gyro, accelerometer, microwave, millimeter, RF standing-wave sensors, resonant LC sensors, capacitive sensors, and/or inductive sensors. In some embodiments, technologies for transmitter sensor 114 and/or receiver sensor 128 include binary sensors that acquire stereoscopic sensor data, such as the location of a human or other sensitive object.

In some embodiments, transmitter sensor 114 and/or receiver sensor 128 is configured for human recognition (e.g., capable of distinguishing between a person and other objects, such as furniture). Examples of sensor data output by human recognition-enabled sensors include: body temperature data, infrared range-finder data, motion data, activity recognition data, silhouette detection and recognition data, gesture data, heart rate data, portable devices data, and wearable device data (e.g., biometric readings and output, accelerometer data).

In some embodiments, transmitters 102 adjust one or more characteristics used to transmit the power waves 116 to ensure compliance with electromagnetic field (EMF) exposure protection standards for human subjects. Maximum exposure limits are defined by US and European standards in terms of power density limits and electric field limits (as well as magnetic field limits). These include, for example, limits established by the Federal Communications Commission (FCC) for maximum permissible exposure (MPE), and limits established by European regulators for radiation exposure. Limits established by the FCC for MPE are codified at 47 CFR § 1.1310. For electromagnetic field (EMF) frequencies in the microwave range, power density can be used to express an intensity of exposure. Power density is defined as power per unit area. For example, power density can be commonly expressed in terms of watts per square meter (W/m²), milliwatts per square centimeter (mW/cm²), or microwatts per square centimeter (μW/cm²). In some embodiments, output from transmitter sensor 114 and/or receiver sensor 128 is used by transmitter 102 to detect whether a person or other sensitive object enters a power transmission region (e.g., a location within a predetermined distance of a transmitter 102, power waves generated by transmitter 102, and/or a pocket of energy). In some embodiments, in response to detecting that a person or other sensitive object has entered the power transmission region, the transmitter 102 adjusts one or more power waves 116 (e.g., by ceasing power wave transmission, reducing power wave transmission, and/or adjusting the one or more characteristics of the power waves). In some embodiments, in response to detecting that a person or other sensitive object has entered the power transmission region, the transmitter 102 activates an alarm (e.g., by transmitting a signal to a loudspeaker that is a component of transmitter 102 or to an alarm device that is remote from transmitter 102). In some embodiments, in response to detecting that a person or other sensitive object has entered a power transmission region, the transmitter 102 transmits a digital message to a system log or administrative computing device.

In some embodiments, antenna array 110 includes multiple antenna elements (e.g., configurable “tiles”) collectively forming an antenna array. Antenna array 110 generates power transmission signals, e.g., RF power waves, ultrasonic power waves, infrared power waves, and/or magnetic resonance power waves. In some embodiments, the antennas of an antenna array 110 (e.g., of a single transmitter, such as transmitter 102 a, and/or of multiple transmitters, such as transmitters 102 a, 102 b, . . . , 102 n) transmit two or more power waves that intersect at a defined location (e.g., a location corresponding to a detected location of a receiver 120), thereby forming a pocket of energy (e.g., a concentration of energy) at the defined location.

In some embodiments, transmitter 102 assigns a first task to a first subset of antenna elements of antenna array 110, a second task to a second subset of antenna elements of antenna array 110, and so on, such that the constituent antennas of antenna array 110 perform different tasks (e.g., determining locations of previously undetected receivers 120 and/or transmitting power waves 116 to one or more receivers 120). As one example, in an antenna array 110 with ten antennas, nine antennas transmit power waves 116 that form a pocket of energy and the tenth antenna operates in conjunction with communications component 112 to identify new receivers in the transmission field. In another example, an antenna array 110 having ten antenna elements is split into two groups of five antenna elements, each of which transmits power waves 116 to two different receivers 120 in the transmission field.

In some embodiments, a microstrip antenna 200 (of FIG. 2) is an antenna element of antenna array 110 of transmitter 102. In some embodiments, a microstrip antenna 200 is an antenna element of antenna 124 of receiver 120. Microstrip antenna 200 transmits and/or receives electromagnetic waves.

FIG. 2 illustrates a cross-sectional view of a microstrip antenna 200, in accordance with some embodiments. In some embodiments, the microstrip antenna 200 includes a first multi-layer printed circuit board (PCB) 202, a second multi-layer PCB 204, and a dielectric slab 206. In some embodiments, the first multi-layer PCB 202 includes first PCB 208. In some embodiments, the first PCB 208 includes electrically conductive material at the top side of first PCB 208 (e.g., a first layer 210 of the electrically conductive material) and at the bottom side of first PCB 208 (e.g., a second layer 212 of the electrically conductive material). In some embodiments, the second multi-layer PCB 204 includes second PCB 214. In some embodiments, the second PCB 214 includes electrically conductive material at the top side of second PCB 214 (e.g., a first layer 216 of the electrically conductive material) and at the bottom side of second PCB 214 (e.g., a second layer 218 of the electrically conductive material). In some embodiments, the electrically conductive material is a metal, for example, copper, silver, gold, aluminum, and/or brass. In some embodiments, the electrically conductive material is laminated on tops and/or bottoms of the PCBs 208 and 214 during manufacture of the first multi-layer PCB 202 and the second multi-layer PCB 204.

In some embodiments, a first set of vias 220 each pass through the first multi-layer PCB 202. In some embodiments, a second set of vias 222 each pass through the second multi-layer PCB 204.

In some embodiments, a first feed 224 passes at least partially through second multi-layer PCB 204, dielectric slab 206, and first multi-layer PCB 202. In some embodiments, a second feed 226 passes at least partially through second multi-layer PCB 204, dielectric slab 206, and first multi-layer PCB 202. For example, a microstrip antenna 200 that is a dual-polarized antenna includes two feeds (e.g., first feed 224 to transmit and/or receive horizontally polarized waves and second feed 226 to transmit and/or receive vertically polarized waves). In some embodiments, a microstrip antenna 200 that is a single-polarized antenna includes only a single feed (e.g., first feed 224). First feed 224 and second feed 226 are, for example, metallic pins.

In some embodiments, a first signal (e.g., a first RF power wave) is provided to first feed 224 via a first cable 228. In some embodiments, first feed 224 excites the microstrip antenna 200 using the first signal for transmission of RF power waves by the microstrip antenna 200. In some embodiments, a second signal (e.g., a second RF power wave) is provided to second feed 226 via a second cable 230. In some embodiments, second feed 226 excites the microstrip antenna 200 using the second signal for transmission of RF power waves by the microstrip antenna 200. In some embodiments, first cable 228 and/or second cable 230 are coupled to an output of processor(s) 104 of transmitter 102 a (processor(s) 102 and transmitter 102 a are discussed in detail above in reference to FIG. 1).

Having a single microstrip antenna with two multi-layer PCBs at opposite ends of a dielectric slab helps to improve manufacturability of antennas. For example, in some embodiments, electrically conductive material is printed on PCBs 208 and 214 using established PCB printing techniques. In some embodiments, any desired slab of material is usable as a substrate (e.g., dielectric substrate 206) to which multi-layer PCBs are attached.

FIG. 3 illustrates a top view of a first multi-layer PCB 202, in accordance with some embodiments. An electrically conductive material (e.g., layer 210) is shown at the top of first PCB 208. FIG. 3 illustrates an embodiment in which first feed 224 and second feed 226 partially puncture first PCB 208, causing distortion of the top surface of first PCB 208. Distortion regions 302 and 304 show locations of first feed 224 and second feed 226, respectively, within the first multi-layer PCB 202.

A first set of vias 220 pass through the first multi-layer PCB 202. In some embodiments, a y-axis distance 306 between vias of the plurality of vias 220 and/or an x-axis distance 308 between vias of the plurality of vias 220 is much smaller than a wavelength λ that corresponds to a target frequency (e.g., 900 MHz) for transmission and/or reception by microstrip antenna 200. Additionally, the microstrip antenna 200 (of which PCB 202 is a component) also has a maximum cross-sectional dimension which is much smaller than this wavelength (as discussed below in reference to FIG. 4). For example, in some embodiments, y-axis distance 306 and/or x-axis distance 308 (or the maximum cross-sectional dimension of the microstrip antenna 200) is equal to or less than λ/0 (e.g., λ/20). In some embodiments, y-axis distance 306 and/or x-axis distance 308 is 2.0 mm. In some embodiments, a diameter of a respective via of the plurality of vias 220 is less than or equal to 2.0 mm (e.g., 1.0 mm).

FIG. 4 illustrates an x-axis dimension 402 and a y-axis dimension 404 of microstrip antenna 200, in accordance with some embodiments. In some embodiments, one or more dimensions of microstrip antenna 200 are determined based on a target bandwidth. For example, in some embodiments, x-axis dimension 402 and/or y-axis dimension 404 is/are much smaller than a wavelength λ that corresponds to a target frequency (e.g., 900 MHz) of power waves transmitted by the microstrip antenna 200. In some embodiments, the microstrip antenna 200 has an x-axis dimension 402 of less than or equal to 50.8 mm (e.g., 40 mm). In some embodiments, the microstrip antenna 200 has a y-axis dimension 404 of less than or equal to 50.8 mm (e.g., 30 mm). For example, in some embodiments, the microstrip antenna 200 has an x-axis dimension 402 of 25.4 mm and a y-axis dimension 404 of 25.4 mm.

FIG. 5 is an expanded cross-sectional view of first multi-layer PCB 202 that illustrates a material formed on an interior surface of at least a subset of vias of the plurality of vias 220, in accordance with some embodiments. In some embodiments, a via-coating material (e.g., via-coating material 502 and 504) is formed on an interior surface of one or more vias (e.g., an interior surface of each via) of the plurality of vias 220. For example, the interior surface of one or more vias is plated with the via-coating material. In some embodiments, the via-coating material is a heat-conducting material and/or an electrically-conductive material. In some embodiments, the via-coating material is conductively coupled to a first electrically conductive material (e.g., electrically conductive material 210 as shown at the top of first PCB 208 and/or electrically conductive material 212 as shown at the bottom of first PCB 208). For example, the via-coating material is conductively coupled to a first electrically conductive material such that heat and/or electrons are conducted between electrically conductive layer 210, the via-coating material, and electrically conductive layer 212. In some embodiments, via-coating material is conductively coupled to a second electrically conductive material (e.g., electrically conductive material 216 as shown at the top of second PCB 214 and/or electrically conductive material 218 as shown at the bottom of second PCB 214). In some embodiments, the via-coating material and the electrically conductive material (e.g., first electrically conductive material and/or second electrically conductive material) are the same material.

FIG. 6 illustrates an array 600 of microstrip antennas, in accordance with some embodiments. In some embodiments, array 600 is used as an antenna array 110 of a transmitter 102 within a wireless power transmission environment 100 as illustrated in FIG. 1 and described above. Array 600 includes a plurality of component antennas, such as multiple microstrip antennas 200 (e.g., first microstrip antenna 200 a, second microstrip antenna 200 b, and third microstrip antenna 200 c). Although three microstrip antennas are shown in FIG. 6, it will be recognized that other numbers of antennas may be included in array 600, e.g., 2-10 antennas.

In some embodiments, formation of array 600 includes arranging the respective multi-layer PCBs of microstrip antennas 200 a, 200 b, and 200 c, and forming a single dielectric slab 206 relative to the respective multi-layer PCBs. For example, the respective multi-layer PCBs are exposed to a liquid state of the dielectric material and a dielectric slab is formed when the dielectric material transitions from a liquid state to a solid state. In other words, the dielectric slab 206 is formed around the respective multi-layer PCBs.

In some embodiments, formation of array 600 includes attaching respective multi-layer PCBs of microstrip antennas 200 a, 200 b, and 200 c to a dielectric slab 206 using an adhesive or other mechanical restraint.

In some embodiments, transmission of RF waves by array 600 is controlled by a plurality of control elements (not shown). In some embodiments, a respective control element of the plurality of control elements includes one or more feeds. For example, a first control element controls first feed 224 and/or second feed 226. In some embodiments, a first control element causes microstrip antenna 200 a to transmit a first RF signal, a second control element causes microstrip antenna 200 b to transmit a second RF signal, and a third control element causes microstrip antenna 200 c to transmit a third RF signal. In some embodiments, the first RF signal is transmitted with at least one characteristic that is distinct from a corresponding characteristic associated with the second RF signal and/or the third RF signal. In some embodiments, the control elements receive signals from processor(s) 104 of transmitter 102. For example, a control element includes an output terminal of processor(s) 104 and/or a communication channel from processor(s) 104 to a microstrip antenna 200.

Although a horizontal arrangement of microstrip antennas 200 a, 200 b, and 200 c is shown in FIG. 6, it will be recognized that alternative arrangements may be used, such as a vertical arrangement of microstrip antennas 200 and/or a grid arrangement of microstrip antennas 200.

In some embodiments, multiple antenna arrays 600 may be included in a respective transmitter 102 and each of the multiple antenna arrays may be configured to transmit power waves at different frequencies (e.g., a first antenna array may be configured to transmit at 900 MHz and a second antenna array may be configured to transmit at 2.4 GHz). To allow for transmission at the different frequencies, each of the multiple antenna arrays may have antennas that are of different dimensions or shapes (e.g., the first antenna array may include larger antennas than the second antenna array).

FIGS. 7A-7C are a flowchart representation of a method 700 for forming an antenna, in accordance with some embodiments.

In some embodiments, forming an antenna optionally includes forming (702-a) a first multi-layer PCB 202 and forming (702-b) a second multi-layer PCB 204. In some embodiments, forming the first multi-layer PCB 202 includes printing a first electrically conductive layer on the top and bottom surfaces of the first multi-layer PCB (e.g., printing the electrically conductive layer as shown at top surface 210 and bottom surface 212 of first PCB 208, FIG. 2). In some embodiments, forming the second multi-layer PCB 204 includes printing the second electrically conductive layer on the top and bottom surfaces of the second multi-layer PCB (e.g., printing the electrically conductive layer as shown at top surface 216 and bottom surface 218 of second PCB 214, FIG. 2).

In some embodiments, forming a multi-layer PCB includes coupling an electrically conductive material (e.g., copper tape or other conductive material) to a substrate (e.g., PCB) by lamination (e.g., using an adhesive such as glue). In some embodiments, a multi-layer PCB is formed using a holding structure such as one or more notches and/or tabs such that an electrically conductive material is physically held in place relative to a substrate by the holding structure.

In some embodiments, forming the first multi-layer PCB 202 optionally includes depositing (704-a) a first heat-conductive material on an interior surface of at least a subset of the first plurality of vias 220. In some embodiments, forming the second multi-layer PCB 204 optionally includes depositing (704-b) a second heat-conductive material on an interior surface of at least a subset of the second plurality of vias 222. For example, a first heat-conductive material is deposited on an interior surface of one or more vias as shown at 502 and 504 of FIG. 5.

In some embodiments, depositing a first heat-conductive material on an interior surface of at least a subset of the first plurality of vias 220 includes depositing (706-a) the first heat-conductive material such that the first heat-conductive material (e.g., as shown at 502 and 504 of FIG. 5) is thermally coupled to the first electrically conductive material (e.g., as shown at 210 and 212 of FIG. 2) of the first multi-layer PCB 202. In some embodiments, depositing a second heat-conductive material on an interior surface of at least a subset of the second plurality of vias includes depositing (706-b) the second heat-conductive material such that the second heat-conductive material is thermally coupled to the second electrically conductive material (e.g., as shown at 216 and 218 of FIG. 2) of the second multi-layer PCB 204. In some embodiments, the heat-conducting material is a metal such as copper, aluminum, brass, steel, and/or bronze.

Turning now to FIG. 7B, in some embodiments, forming an antenna includes forming (708) a dielectric assembly by coupling a dielectric slab 206 to a first multi-layer PCB 202 and a second multi-layer PCB 204. The first multi-layer PCB 202 includes (708-a) a top surface and a bottom surface that is opposite the top surface. The top and bottom surfaces of the first multi-layer PCB 202 include a first electrically conductive material (e.g., as shown at 210 and 212 of FIG. 2). A first plurality of vias 220 each substantially pass through the top and bottom surfaces of the first multi-layer PCB 202. The second multi-layer PCB 204 includes (708-b) a top surface and a bottom surface that is opposite the top surface. The top and bottom surfaces of the second multi-layer PCT 204 include a second electrically conductive material (e.g., as shown at 216 and 218 of FIG. 2). A second plurality of vias 222 each substantially pass through the top and bottom surfaces of the second multi-layer PCB 204.

In some embodiments, dielectric slab 206 includes a dielectric material fabricated from an exotic and/or synthetic material, such as a material that has a high dielectric constant (e.g., a moldable ceramic). For example, in some embodiments, dielectric slab 206 has a dielectric constant between 1.0 and 40 (e.g., a dielectric constant of 30). In some embodiments, the dielectric slab 206 is formed from stone, ceramic, plastic, and/or glass, or gas (e.g., in a container). In some embodiments, dielectric slab 206 is fabricated from a material that is capable of insulating, reflecting, and/or absorbing electric current. In some embodiments, dielectric slab 206 is fabricated from one or more materials that are engineered to yield predetermined magnetic permeability and/or electrical permittivity values. In some embodiments, at least one of a magnetic permeability value or an electrical permittivity value of dielectric slab 206 is based upon at least one predetermined power-transfer requirement and/or compliance constraint (e.g., in compliance with one or more government regulations).

In some embodiments, coupling the dielectric slab 206 to the first multi-layer PCB 202 and the second multi-layer PCB 204 optionally includes (710) coupling the first multi-layer PCB 202 to the dielectric slab 206 using an adhesive (e.g., glue, epoxy, potting compound, or other suitable adhesive) and coupling the second multi-layer PCB 204 to the dielectric slab 206 using the adhesive.

In some embodiments, coupling the dielectric slab 206 to the first multi-layer PCB 202 and the second multi-layer PCB 204 optionally includes (712) arranging the first multi-layer PCB 202 and the second multi-layer PCB 204 relative to dielectric material while it is in a liquid state, wherein the first multi-layer PCB 202 and the second multi-layer PCB 204 have fixed positions within the dielectric slab 206 after the dielectric material of the dielectric slab 206 transitions from the liquid state to a solid state. For example, the dielectric material of dielectric slab 206 is a ceramic, plastic, or other state-changing material that is capable of transitioning from a liquid state to a set solid state. In some embodiments, the first multi-layer PCB 202 and the second multi-layer PCB 204 are coupled to the dielectric slab 206 by molding the dielectric material around the first multi-layer PCB 202 and the second multi-layer PCB 204. For example, the dielectric slab 206 is shaped to include two reservoirs that are configured to receive the first and second multi-layer PCBs and the dielectric slab 206 is then baked so that the first and second multi-layer PCBs are then securely attached within the respective reservoirs of the dielectric slab 206.

In some embodiments, forming an antenna includes coupling (714) at least one feed (e.g., first feed 224 and/or second feed 226) to the dielectric assembly (e.g., dielectric slab 206, first multi-layer PCB 202, and second multi-layer PCB 204). For example, the at least one feed is coupled to the dielectric assembly by inserting the at least one feed into the dielectric assembly (e.g., by drilling one or more holes at least partially through the dielectric slab 206, first multi-layer PCB 202, and second multi-layer PCB 204 and inserting the at least one feed into the one or more holes). In some embodiments, the at least one feed is coupled to the dielectric assembly by attaching the at least one feed to a surface of dielectric slab 206, first multi-layer PCB 202, and/or second multi-layer PCB 204 with adhesive or other coupling means.

In some embodiments, coupling the at least one feed to the dielectric assembly optionally includes inserting (716) the at least one feed into the dielectric assembly such that the at least one feed (e.g., first feed 224 and/or second feed 226) at least partially passes through at least one of: the first multi-layer PCB 202, the dielectric slab 206, or the second multi-layer PCB 204. For example, in FIG. 2, first feed 224 and second feed 226 are shown passing fully through second multi-layer PCB 204, passing fully through the dielectric slab 206, and passing partially through first multi-layer PCB 202.

In some embodiments, the at least one feed substantially (e.g., at least halfway) passes through (718) the first multi-layer PCB 202, the second multi-layer PCB 204, and the dielectric slab 206. For example, a feed substantially passes through a multi-layer PCB when the feed passes at least halfway from the bottom of the multi-layer PCB to the top of the multi-layer PCB.

In some embodiments, the first and second feeds are coupled to a power source and/or waveform generator (e.g., the power source and waveform generator described above in reference to FIG. 1) that provides a signal for transmission by an assembled antenna (e.g., microstrip antenna 200, FIG. 2).

The preceding description of the disclosed embodiments is provided to enable any person skilled in the art to make or use the embodiments described herein and variations thereof. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other embodiments without departing from the spirit or scope of the subject matter disclosed herein. Thus, the present disclosure is not intended to be limited to the embodiments shown herein but is to be accorded the widest scope consistent with the following claims and the principles and novel features disclosed herein.

Features of the present invention can be implemented in, using, or with the assistance of a computer program product, such as a storage medium (media) or computer readable storage medium (media) having instructions stored thereon/in which can be used to program a processing system to perform any of the features presented herein. The storage medium (e.g., memory 106) can include, but is not limited to, high-speed random access memory, such as DRAM, SRAM, DDR RAM or other random access solid state memory devices, and may include non-volatile memory, such as one or more magnetic disk storage devices, optical disk storage devices, flash memory devices, or other non-volatile solid state storage devices. Memory (e.g., 106, 134, and/or 142) optionally includes one or more storage devices remotely located from the CPU(s) (e.g., processor(s) 104, 132, and/or 140). Memory (e.g., 106, 134, and/or 142), or alternatively the non-volatile memory device(s) within the memory, comprises a non-transitory computer readable storage medium.

Stored on any one of the machine readable medium (media), features of the present invention can be incorporated in software and/or firmware for controlling the hardware of a processing system (such as the components associated with the transmitters 102 and/or receivers 120), and for enabling a processing system to interact with other mechanisms utilizing the results of the present invention. Such software or firmware may include, but is not limited to, application code, device drivers, operating systems, and execution environments/containers.

Communication systems as referred to herein (e.g., communications components 112, 136, and/or 144) optionally communicate via wired and/or wireless communication connections. Communication systems optionally communicate with networks, such as the Internet, also referred to as the World Wide Web (WWW), an intranet and/or a wireless network, such as a cellular telephone network, a wireless local area network (LAN) and/or a metropolitan area network (MAN), and other devices by wireless communication. Wireless communication connections optionally use any of a plurality of communications standards, protocols and technologies, including but not limited to radio-frequency (RF), radio-frequency identification (RFID), infrared, radar, sound, Global System for Mobile Communications (GSM), Enhanced Data GSM Environment (EDGE), high-speed downlink packet access (HSDPA), high-speed uplink packet access (HSUPA), Evolution, Data-Only (EV-DO), HSPA, HSPA+, Dual-Cell HSPA (DC-HSPDA), long term evolution (LTE), near field communication (NFC), ZigBee, wideband code division multiple access (W-CDMA), code division multiple access (CDMA), time division multiple access (TDMA), Bluetooth, Wireless Fidelity (Wi-Fi) (e.g., IEEE 102.11a, IEEE 102.11ac, IEEE 102.11ax, IEEE 102.11b, IEEE 102.11g and/or IEEE 102.11n), voice over Internet Protocol (VoIP), Wi-MAX, a protocol for e-mail (e.g., Internet message access protocol (IMAP) and/or post office protocol (POP)), instant messaging (e.g., extensible messaging and presence protocol (XMPP), Session Initiation Protocol for Instant Messaging and Presence Leveraging Extensions (SIMPLE), Instant Messaging and Presence Service (IMPS)), and/or Short Message Service (SMS), or any other suitable communication protocol, including communication protocols not yet developed as of the filing date of this document.

It will be understood that, although the terms “first,” “second,” etc. may be used herein to describe various elements, these elements should not be limited by these terms. These terms are only used to distinguish one element from another.

The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the claims. As used in the description of the embodiments and the appended claims, the singular forms “a,” “an” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will also be understood that the term “and/or” as used herein refers to and encompasses any and all possible combinations of one or more of the associated listed items. It will be further understood that the terms “comprises” and/or “comprising,” when used in this specification, specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof.

As used herein, the term “if” may be construed to mean “when” or “upon” or “in response to determining” or “in accordance with a determination” or “in response to detecting,” that a stated condition precedent is true, depending on the context. Similarly, the phrase “if it is determined [that a stated condition precedent is true]” or “if [a stated condition precedent is true]” or “when [a stated condition precedent is true]” may be construed to mean “upon determining” or “in response to determining” or “in accordance with a determination” or “upon detecting” or “in response to detecting” that the stated condition precedent is true, depending on the context.

The foregoing description, for purpose of explanation, has been described with reference to specific embodiments. However, the illustrative discussions above are not intended to be exhaustive or to limit the claims to the precise forms disclosed. Many modifications and variations are possible in view of the above teachings. The embodiments were chosen and described in order to best explain principles of operation and practical applications, to thereby enable others skilled in the art. 

What is claimed is:
 1. An antenna for use in a wireless power transmission system, the antenna comprising: a first multi-layer printed circuit board (PCB) that includes at least a first surface with a first electrically conductive material; a second multi-layer PCB that includes at least a second surface with a second electrically conductive material, wherein the second multi-layer PCB is separate and distinct from the first multi-layer PCB; a first plurality of vias that each substantially pass through the top and bottom surfaces of the first multi-layer PCB; a second plurality of vias that each substantially pass through the top and bottom surfaces of the second multi-layer PCB, wherein the second plurality of vias is separate and distinct from the first plurality of vias; a dielectric slab that is configured to receive: the first multi-layer PCB, and the second multi-layer PCB; and a first feed that (i) at least partially passes through each of the first multi-layer PCB, the second multi-layer PCB, and the dielectric slab, and (ii) contacts at least one via of the first plurality of vias and at least one via of the second plurality of vias, wherein the first feed delivers a radio frequency (RF) signal at a predetermined frequency to the antenna, wherein the antenna is configured to transmit the RF signal for delivering wireless power to at least one remote receiver device, and the at least one remote receiver device is configured to convert the RF signal into usable power for providing power or charge to the at least one remote receiver device.
 2. The antenna of claim 1, wherein a maximum cross-sectional dimension of the antenna is less than a wavelength corresponding to the predetermined frequency.
 3. The antenna of claim 2, wherein a maximum cross-sectional dimension of the antenna is less than 1/10 of the wavelength corresponding to the predetermined frequency.
 4. The antenna of claim 3, wherein the maximum cross-sectional dimension of the antenna is less than 1/20 of the wavelength corresponding to the predetermined frequency.
 5. The antenna of claim 1, including a second feed that is coupled to the antenna, wherein the second feed is configured to provide an additional RF signal at the predetermined frequency to the antenna.
 6. The antenna of claim 1, wherein a first diameter of at least a subset of vias of the first and second pluralities of vias corresponds to the predetermined frequency.
 7. The antenna of claim 1, wherein a spacing between respective adjacent vias of the first and second pluralities of vias corresponds to the predetermined frequency.
 8. The antenna of claim 1, wherein: the wireless power transmission system includes a transmitter that includes: a plurality of component antennas, wherein the antenna is a first component antenna of the plurality of component antennas; and a plurality of control elements; a first control element of the plurality of control elements is configured to cause the first component antenna to transmit a first RF signal; and a second control element of the plurality of control elements is configured to cause a second component antenna of the plurality of component antennas to transmit a second RF signal, wherein the second RF signal is transmitted with at least one characteristic that is distinct from a corresponding characteristic associated with the first RF signal.
 9. The antenna of claim 1, wherein a first heat-conductive material is coupled to an interior surface of at least one via of the first and second pluralities of vias.
 10. The antenna of claim 9, wherein: at least one of the first multi-layer PCB and the second multi-layer PCB includes a second heat-conductive material; and the second heat-conductive material is thermally coupled to the first heat-conductive material that is coupled to the at least one via of the first and second pluralities of vias.
 11. The antenna of claim 10, wherein the second heat-conductive material is included in at least one of the first electrically conductive material or the second electrically conductive material.
 12. The antenna of claim 1, wherein the first and second multi-layer PCBs are secured to the dielectric slab at opposite ends of the dielectric slab.
 13. A method for forming an antenna, comprising: forming a dielectric assembly by coupling a dielectric slab to a first multi-layer printed circuit board (PCB) and a second multi-layer PCB, wherein the second multi-layer PCB is separate and distinct from the first multi-layer PCB, and wherein: the first multi-layer PCB includes at least a first surface, wherein: the first surface of the first multi-layer PCB includes a first electrically conductive material, and a first plurality of vias each substantially pass through the first surface of the first multi-layer PCB; and the second multi-layer PCB includes at least a second surface, wherein: the second surface of the second multi-layer PCB includes a second electrically conductive material, and a second plurality of vias that each substantially pass through the second surface of the second multi-layer PCB, wherein the second plurality of vias is separate and distinct from the first plurality of vias; and coupling a first feed to the dielectric assembly, wherein the first feed (i) at least partially passes through each of the first multi-layer PCB, the dielectric slab, and the second multi-layer PCB, and (ii) contacts at least one via of the first plurality of vias and at least one via of the second plurality of vias, and further wherein the first feed delivers a radio frequency (RF) signal at a predetermined frequency to the antenna, wherein the antenna is configured to transmit the RF signal for delivering wireless power to at least one remote receiver device, and the at least one remote receiver device is configured to convert the RF signal into usable power for providing power or charge to the at least one remote receiver device.
 14. The method of claim 13, wherein coupling the dielectric slab to the first multi-layer PCB and the second multi-layer PCB includes: coupling the first multi-layer PCB to the dielectric slab using an adhesive; and coupling the second multi-layer PCB to the dielectric slab using the adhesive.
 15. The method of claim 13, wherein coupling the dielectric slab to the first multi-layer PCB and the second multi-layer PCB includes: arranging the first multi-layer PCB and the second multi-layer PCB relative to a dielectric material while it is in a liquid state, wherein the first multi-layer PCB and the second multi-layer PCB have fixed positions within the dielectric slab after the dielectric material of the dielectric slab transitions from the liquid state to a solid state.
 16. The method of claim 13, including: forming the first multi-layer PCB, wherein forming the first multi-layer PCB includes printing the first electrically conductive layer on the first surface of the first multi-layer PCB, and forming the second multi-layer PCB, wherein forming the second multi-layer PCB includes printing the second electrically conductive layer on the second surface of the second multi-layer PCB.
 17. The method of claim 13, including: forming the first multi-layer PCB includes depositing a first heat-conductive material on an interior surface of at least a subset of the first plurality of vias, and forming the second multi-layer PCB includes depositing a second heat-conductive material on an interior surface of at least a subset of the second plurality of vias.
 18. The method of claim 17, wherein: depositing a first heat-conductive material on an interior surface of at least a subset of the first plurality of vias includes depositing the first heat-conductive material such that the first heat-conductive material is thermally coupled to the first electrically conductive material of the first multi-layer PCB; and depositing a second heat-conductive material on an interior surface of at least a subset of the second plurality of vias includes depositing the second heat-conductive material such that the second heat-conductive material is thermally coupled to the second electrically conductive material of the second multi-layer PCB. 